// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys
if (!Object.keys) {
    Object.keys = (function () {
        var hasOwnProperty = Object.prototype.hasOwnProperty,
            hasDontEnumBug = !({toString: null}).propertyIsEnumerable('toString'),
            dontEnums = [
                'toString',
                'toLocaleString',
                'valueOf',
                'hasOwnProperty',
                'isPrototypeOf',
                'propertyIsEnumerable',
                'constructor'
            ],
            dontEnumsLength = dontEnums.length;

        return function (obj) {
            if (typeof obj !== 'object' && typeof obj !== 'function' || obj === null) throw new TypeError('Object.keys called on non-object');

            var result = [];

            for (var prop in obj) {
                if (hasOwnProperty.call(obj, prop)) result.push(prop);
            }

            if (hasDontEnumBug) {
                for (var i=0; i < dontEnumsLength; i++) {
                    if (hasOwnProperty.call(obj, dontEnums[i])) result.push(dontEnums[i]);
                }
            }
            return result;
        };
    })();
}

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
if (!Array.prototype.filter)
{
    Array.prototype.filter = function(fun /*, thisp */)
    {
        "use strict";

        if (this == null)
            throw new TypeError();

        var t = Object(this);
        var len = t.length >>> 0;
        if (typeof fun != "function")
            throw new TypeError();

        var res = [];
        var thisp = arguments[1];
        for (var i = 0; i < len; i++)
        {
            if (i in t)
            {
                var val = t[i]; // in case fun mutates this
                if (fun.call(thisp, val, i, t))
                    res.push(val);
            }
        }

        return res;
    };
}

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/Trim
if (!String.prototype.trim) {
    String.prototype.trim = function () {
        return this.replace(/^\s+|\s+$/g, '');
    };
}

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach
if (!Array.prototype.forEach)
{
    Array.prototype.forEach = function(fun /*, thisArg */)
    {
        "use strict";

        if (this === void 0 || this === null)
            throw new TypeError();

        var t = Object(this);
        var len = t.length >>> 0;
        if (typeof fun !== "function")
            throw new TypeError();

        var thisArg = arguments.length >= 2 ? arguments[1] : void 0;
        for (var i = 0; i < len; i++)
        {
            if (i in t)
                fun.call(thisArg, t[i], i, t);
        }
    };
}

// Production steps of ECMA-262, Edition 5, 15.4.4.19
// Reference: http://es5.github.com/#x15.4.4.19
if (!Array.prototype.map) {
    Array.prototype.map = function(callback, thisArg) {

        var T, A, k;

        if (this == null) {
            throw new TypeError(" this is null or not defined");
        }

        // 1. Let O be the result of calling ToObject passing the |this| value as the argument.
        var O = Object(this);

        // 2. Let lenValue be the result of calling the Get internal method of O with the argument "length".
        // 3. Let len be ToUint32(lenValue).
        var len = O.length >>> 0;

        // 4. If IsCallable(callback) is false, throw a TypeError exception.
        // See: http://es5.github.com/#x9.11
        if (typeof callback !== "function") {
            throw new TypeError(callback + " is not a function");
        }

        // 5. If thisArg was supplied, let T be thisArg; else let T be undefined.
        if (thisArg) {
            T = thisArg;
        }

        // 6. Let A be a new array created as if by the expression new Array(len) where Array is
        // the standard built-in constructor with that name and len is the value of len.
        A = new Array(len);

        // 7. Let k be 0
        k = 0;

        // 8. Repeat, while k < len
        while(k < len) {

            var kValue, mappedValue;

            // a. Let Pk be ToString(k).
            //   This is implicit for LHS operands of the in operator
            // b. Let kPresent be the result of calling the HasProperty internal method of O with argument Pk.
            //   This step can be combined with c
            // c. If kPresent is true, then
            if (k in O) {

                // i. Let kValue be the result of calling the Get internal method of O with argument Pk.
                kValue = O[ k ];

                // ii. Let mappedValue be the result of calling the Call internal method of callback
                // with T as the this value and argument list containing kValue, k, and O.
                mappedValue = callback.call(T, kValue, k, O);

                // iii. Call the DefineOwnProperty internal method of A with arguments
                // Pk, Property Descriptor {Value: mappedValue, : true, Enumerable: true, Configurable: true},
                // and false.

                // In browsers that support Object.defineProperty, use the following:
                // Object.defineProperty(A, Pk, { value: mappedValue, writable: true, enumerable: true, configurable: true });

                // For best browser support, use the following:
                A[ k ] = mappedValue;
            }
            // d. Increase k by 1.
            k++;
        }

        // 9. return A
        return A;
    };
}

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf
if (!Array.prototype.indexOf) {
    Array.prototype.indexOf = function (searchElement, fromIndex) {
        if ( this === undefined || this === null ) {
            throw new TypeError( '"this" is null or not defined' );
        }

        var length = this.length >>> 0; // Hack to convert object.length to a UInt32

        fromIndex = +fromIndex || 0;

        if (Math.abs(fromIndex) === Infinity) {
            fromIndex = 0;
        }

        if (fromIndex < 0) {
            fromIndex += length;
            if (fromIndex < 0) {
                fromIndex = 0;
            }
        }

        for (;fromIndex < length; fromIndex++) {
            if (this[fromIndex] === searchElement) {
                return fromIndex;
            }
        }

        return -1;
    };
}
// Based on https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray

if (! Array.isArray) {
    Array.isArray = function(obj) {
        return Object.prototype.toString.call(obj) === "[object Array]";
    };
}

// https://github.com/ttaubert/node-arraybuffer-slice
// (c) 2013 Tim Taubert <tim@timtaubert.de>
// arraybuffer-slice may be freely distributed under the MIT license.

"use strict";

if (typeof ArrayBuffer !== 'undefined' && !ArrayBuffer.prototype.slice) {
    ArrayBuffer.prototype.slice = function (begin, end) {
        begin = (begin|0) || 0;
        var num = this.byteLength;
        end = end === (void 0) ? num : (end|0);

        // Handle negative values.
        if (begin < 0) begin += num;
        if (end < 0) end += num;

        if (num === 0 || begin >= num || begin >= end) {
            return new ArrayBuffer(0);
        }

        var length = Math.min(num - begin, end - begin);
        var target = new ArrayBuffer(length);
        var targetArray = new Uint8Array(target);
        targetArray.set(new Uint8Array(this, begin, length));
        return target;
    };
}
